The invention relates to a large heat resistant outdoor cooking device capable of burning mesquite charcoal, and the like, at high temperatures by preventing burnout of the firebox walls.
A wide variety of fuel sources have been used in large volume outdoor cooking devices such as charcoal, wood, bottle gas and mesquite charcoal. Conventional oven designs can accommodate the combustion temperatures of charcoal and most woods. However, when materials that burn at higher temperatures, such as mesquite charcoal, are utilized, the heat created can cause the temperature to rise up to about 1500.degree. F. within the firebox. In prior art cooking devices, burnout of the firebox walls has been a problem.
Recently, mesquite barbecuing has become very popular. Mesquite is a dry shrub that grows wild in the southwest United States and Mexico and is usually purchased in charcoal form for barbecuing. The hotter fire created by burning mesquite makes possible a quick searing of meat, for example, and thereby allowing a retention of more of the natural juices in the meat. Mesquite is acclaimed as providing a delicate sweet and smokey flavor to the barbecued food. Unfortunately, conventional barbecue grills and ovens are susceptible to the heat degradation caused by burning this material.
Heretofore, outdoor cooking devices have primarily relied upon using heavy gauge sheet steel for the firebox walls, which are sometimes treated with a heat resistant paint to prevent burnout. With the higher temperatures caused by mesquite and certain types of woods, such as hickory chips, oak, and the like, it is impractical to simply provide thicker firebox walls because temperature differentials cuasing hot spots can still create localized warpage and damage even though the heavier gauge materials are used. Additionally, the cost of heavier gauge sheet steel precludes the manufacture of a product that is economically competetive.
It would therefore be desirable to use a standard size sheet steel for the firebox, such as 12 gauge, but yet provide an insulating barrier between the firebox walls and the source of heat to avoid the burnout problem.
The present invention solves the problem of firebox burnout by providing heavy duty liner sheet means adjacent the firebox side walls and a cooperative burning grate for accommodating mesquite or the like, to be spaced safely above the bottom wall of the firebox.
The liner sheet means and grate are arranged whereby sections of each may be individually removed and replaced, if damaged, without the necessity of major repair to the firebox or the discarding of an entire cooking device should burnout occur. Additionally, the liner sheet means and burning grate are provided to be adjustable, in one form of the invention, whereby the combustible material may be disposed at different levels relative to a cooking grill assembly supported above firebox.
Should any one of the sections of liner sheet means or the grate become damaged, any one may be easily replaced and thus avoid previous repair practices of welding cover plates over burnout holes, such as occurs in prior art firebox designs for conventional cooking devices.
In summary, the invention provides for a mesquite burning outdoor cooking device having a firebox defined by four side walls and adapted to be optionally covered by a hinged lid. The bottom of the firebox comprises a generally planar bottom wall joined to the side walls and extending below a grill assembly supported above the side walls. Spaced interiorly from the firebox side walls, liner sheet means is provided whereby to define an insulative spacing between the firebox side walls and liner sheet means and wherein at each of the four firebox side walls, a section of the liner sheet means is separately removable for repair and replacement if needed. Opposing sections of the liner sheet means provide support shelf means for a burning grate, or a plurality of burning grate sections, to be arranged for the support of mesquite, or the like, at a safe distance above the bottom wall of the firebox in order to prevent hot spots from occuring on the bottom wall and avoid burnout. The burning grate is arranged to extend across substantially the entire surface area of the bottom wall and is supportively spaced inwardly of the liner sheet means whereby an insulative spacing is created adjacent to substantially all of the firebox interior surfaces.
In one embodiment of the invention, the firebox is relatively shallow, such as about six to eight inches deep, and a burning grate is provided to be arranged at a fixed elevation within the firebox. The embodiment provides for a portabile cooking device by including caster leg means extending below the firebox so that the cooking device may be easily moved.
In another embodiment, a deeper firebox is provided whereby a burning grate may be arranged at a plurality of elevations relative to the bottom wall of the firebox. In this embodiment, the depth of the firebox is preferably about 18 to 24 inches deep whereby to allow for the utilization of large wood logs to be burned inside the firebox. At opposite end walls of the firebox, hinged doors are provided whereby access to the interior of the firebox is achieved without distrubing a grill assembly above. This access provision allows for maintenace and also for the introduction of additional wood or mesquite when required during cooking. Sections of the liner sheet means are arranged along longer front and back walls of the firebox and spaced therefrom whereby to cooperate with transverse shorter sections of the liner sheet means arranged at the opposite end walls. The end wall liner sheet sections provide for the insulation of the doors and the end walls whereby the end walls and door are protected from the high heat while allowing the doors to be opened during cooking. The liner sheet means for this alternate embodiment of the invention similarly provides for individual replacement of liner sheet sections.
The alternate embodiment for the mesquite burning outdoor device may be made to be movable by the inclusion of caster leg means supportively extending below the firebox or, optionally, an automobiletype trailer may be employed wherein the firebox is supported by the trailer frame so that the cooking device may be transported long distances and to remote sites.
In all embodiments of the invention, the exterior surfaces of the firebox remains relatively cool to the touch, while burning mesquite charcoal at temperatures considerably higher than those normally experienced with charcoal or bottled gas so that the side walls of the firebox do not become so hot as to create a hazard to the cook or damage to the firebox.